With an intent to develop effective prophylaxis or treatment of allergic diseases including allergic asthma, our goal is to examine the safety and efficacy of chitosan IFN-gamma-pDNA nanosphere (CIN) Therapy and the cellular and molecular mechanisms underlying its effectiveness in a mouse model of asthma. Deviation of immune response to allergens from a pathogenic T helper-2 type response to T helper-1 type may provide a practical approach to modifying the course of disease. Administration of IFN-gamma, and IL-12 DNA plasmids significantly decreased airway inflammation and airway hyperresponsiveness in a mouse model of grass allergic asthma. In addition, Adenoviral-mediated IFN-gamma, gene transfer effectively reversed established asthma in BALB/c mouse model. While these studies aid in the mechanistic understanding of IFN-gamma, action in the lung, acute inflammation and immunogenicity to virus remains the major obstacle for the application of viral-mediated gene transfer for treating human asthma. We therefore developed a non-viral strategy that involves the development of chitosan nanospheres containing IFN-gamma, pDNA (CIN), intranasally (i.n.) delivered to the lung, as a strategy for asthma treatment. Our working hypothesis is that i.n. CIN therapy provides for effective prophylaxis or treatment of asthma by inducing changes in expression of cytokine and chemokine genes which result in altered antigen presentation, decreased migration of effector cells into the lung, and apoptosis of inflammatory cells, leading to a global decrease in inflammation and airway remodeling. The specific aims of this research program are as follows: Aim #1. Evaluate chitosan-IFN-gamma-pDNA nanospheres (CIN) as a prophylactic or a therapeutic modality for allergic disease in BALB/c mice. We plan to evaluate the role of CIN in prophylaxis/therapy of allergic asthma in BALB/c mice with respect to magnitude of acute inflammation, duration of protection from asthma and its potential in a chronic asthma model. We will analyze different asthma phenotypes, such as immune deviation of allergic response revealed by a change in T-cell cytokine secretion and antibody response profiles, the airway hyperreactivity and eosinophils in broncho-alveolar lavage, and lung pathology. Aim #2. Elucidate the cellular/molecular mechanism of CIN-induced immunomodulation. We plan to examine the role of T cells, CIN modulation of specific T cell response in the lung including apoptosis of Th2 cells and modulation of the number and activity of dendritic cells in the lung. Aim #3. Elucidate the anti-inflammatory mechanism of CIN-induced protection. We plan to examine the genes, which mediate the effects of CIN, whether CIN affects airway inflammation and airway remodeling in lungs of mice, and whether CIN induces apoptosis of mucus producing goblet cells. It is anticipated that the results of these studies will contribute significantly to our knowledge of asthma and CIN therapy may provide a major breakthrough in management of asthma.